A rapid calculation method for the load of a building cluster

Abstract

The present invention discloses a rapid calculation method for the load of a building cluster. The method first obtains the main parameters of the enclosure structures of each individual building in the building cluster and weather data; constructs a one-dimensional steady-state heat transfer equation to calculate the basic heat consumption of the building enclosure structure, and makes additional corrections from three aspects: orientation, wind force, and height; uses the cooling load coefficient method based on the Z transfer function to calculate the cooling load formed by heat transfer through the enclosure structure and solar heat gain through the external windows, and the cooling load formed by heat dissipation from the human body, lighting, and equipment; establishes a calculation model for the infiltration load of the heat and mass exchange between the internal air of the building and the external environment; establishes a calculation model for the heating and cooling load of the building based on the grand canonical ensemble theory; obtains the historical data set of the building load, compares the load calculation results of the model of the present invention, introduces a correction coefficient η to correct the model, and then superimposes the loads of each individual building to obtain the load of the building cluster. The present invention can achieve rapid calculation and accurate evaluation of the load of the building cluster.

Description

Technical Field

[0001] The present invention belongs to the field of building load prediction calculation, and particularly relates to a method for quickly calculating the cooling and heating loads of a building cluster. Background Art

[0002] The contribution of the construction industry to global energy consumption has been increasing year by year and it has now become the world's largest energy consumer. The energy consumption of the construction industry accounts for 36% of the total global final energy consumption and 37% of the energy-related CO 2 emissions. Currently, the building energy consumption in China accounts for as high as 1 / 3 of the total primary energy consumption in the whole society. Among them, the building operation energy consumption such as heating, ventilation, and air conditioning accounts for more than two-thirds of the total energy consumption in the whole process of buildings. Using load modeling to accurately calculate and predict the cooling and heating loads of buildings is of great significance for the control of the indoor thermal environment of buildings and the reduction of building energy consumption.

[0003] The existing building load calculation and modeling methods are mainly the mechanism modeling method based on the heat transfer principle and the characteristics of the maintenance structure and the data-driven modeling method. The mechanism modeling method has clear physical concepts, complex calculation processes, and poor ability to reflect the randomness of dynamic loads. At the same time, in order to make the model easy to solve, the existing mechanism load calculation method simplifies the infiltration load calculation, resulting in a deviation between the load calculation result and the actual situation. The data-driven method makes full use of the system operation data, but depends on the accuracy of historical data, and the model generalization ability and interpretability are poor. Summary of the Invention

[0004] Aiming at the problems of the mechanism load model and the data-driven model, as well as the defect of simplifying the infiltration load calculation in the existing building load calculation method. The present invention comprehensively considers the advantages and disadvantages of the two modeling methods, and based on the grand canonical ensemble theory, takes the indoor air of the building as the main body of load calculation research, and proposes a method for quickly calculating the cluster load in the building energy system.

[0005] The present invention is realized by adopting the following technical solutions:

[0006] The present invention discloses a method for quickly calculating the load of a building cluster, including the following steps:

[0007] Step S1, obtaining the main parameters of the enclosure structure and weather data of each individual building in the building cluster to facilitate the calculation of the cooling and heating loads of the buildings;

[0008] Step S2, constructing a one-dimensional steady-state heat transfer equation to calculate the basic heat consumption of the building enclosure structure, and making additional corrections from three aspects: orientation, wind force, and height;

[0009] Step S3, using the cooling load coefficient method based on the Z transfer function to calculate the cooling load formed by heat transfer through the enclosure structure and solar heat gain through the outer window, as well as the cooling load formed by heat dissipation from the human body, lighting, and equipment;

[0010] Step S4: Based on the grand canonical ensemble theory, construct a calculation model for the infiltration load of heat and mass transfer between the indoor air of the building and the external environment, and calculate the infiltration load.

[0011] Step S5: Integrate the above steps to establish a calculation model for the heating and cooling loads of the building based on the grand canonical ensemble theory.

[0012] Step S6: Obtain the historical data set of the heating and cooling loads of the building, compare the load calculation results of the model constructed in S5, introduce a correction coefficient η to correct the model, and superimpose the loads of each individual building in the building cluster to obtain the load of the building cluster.

[0013] In the above technical solution, further, the specific content of step S1 is as follows:

[0014] The main parameters of the envelope structures of each individual building in the building cluster include the composition materials, areas, window-wall ratios, and shape factors of the envelope structures of each part of the building, as well as the heat transfer coefficient K of each part.

[0015] The weather data is the weather data of the area where the building is located, including hourly dry bulb temperature, pressure, and wind speed data. Obtaining the above data facilitates the subsequent calculation of the heating and cooling loads of the building.

[0016] Furthermore, the specific content of step S2 includes the following steps:

[0017] Step S21: In the case of centralized heating, construct a one-dimensional steady-state heat transfer equation for each part of the envelope structure, as shown in Equation (1), to obtain the basic heat consumption Q of the building envelope j :

[0018] Q j = KF(t n - t w )α (1)

[0019] In the formula, K is the heat transfer coefficient of the external wall, roof, or external window [W / (m 2 ·K)], F is the heat transfer area of the external wall, roof, or external window (m 2 ), t n is the indoor temperature; t w is the outdoor temperature; α is the temperature difference correction coefficient, which can be obtained from the "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings" (hereinafter referred to as the "Code").

[0020] Step S22: The actual heat consumption will be affected by different factors such as meteorological conditions and the actual situation of the building, and it is necessary to correct the basic heat consumption. Obtain the orientation correction coefficient β of the building from the "Code" ch , the wind force additional coefficient β f and the height additional coefficient βfg , the actual heat consumption Q is further calculated from Equation (2). 1 :

[0021] Q 1 = Q j (1 + β ch + β f )(1 + β fg ) (2)

[0022] Furthermore, the step S3 specifically includes the following steps:

[0023] Step S31, calculate the cooling load formed by the heat transfer of the exterior wall, roof, and exterior window through the steady-state heat transfer equation (3).

[0024] CL W = KF(t wl - t n ) (3)

[0025] In the formula, K is the heat transfer coefficient of the exterior wall, roof, or exterior window [W / (m 2 ·K)], F is the heat transfer area of the exterior wall, roof, or exterior window (m 2 ), and t wl is the hourly cooling load calculation temperature of the exterior wall, roof, or exterior window.

[0026] Step S32, calculate the cooling load formed by the solar heat gain through the exterior window, as shown in Equation (4):

[0027] CL c = C clC C z D Jmax F c (4)

[0028] C z = C w C n C s (5)

[0029] In the formula, CL c is the hourly cooling load formed by the solar radiation heat gain through the glass window, C clC is the solar radiation cooling load coefficient through the standard glass without shading, C z is the comprehensive shading coefficient of the exterior window, C w is the exterior shading correction coefficient, C n is the interior shading correction coefficient, C s is the glass correction coefficient, D Jmax is the maximum value of the solar heat gain factor in summer, all of which can be obtained from the "Code", and F c is the net area of the window glass (m 2 ).

[0030] In step S33, the cooling load formed by the human body, lighting, and equipment heat dissipation can be calculated according to formulas (6), (7), and (8):

[0031]

[0032] CL zm = C clzm C zm Q zm (7)

[0033] CL sb = C clsb C sb Q sb (8)

[0034] In the formula, CL rt , CL zm , and CL sb are the hourly cooling loads formed by the human body, lighting, and equipment heat dissipation, respectively (W); n is the number of people, is the clustering coefficient; are the human body, lighting, and equipment cooling load coefficients, respectively. C zm and C sb are the lighting and equipment correction coefficients, respectively. Q rt , Q zm , and Q sb are the heat dissipations of the human body, lighting, and equipment, respectively (W).

[0035] Furthermore, step S4 specifically includes the following steps:

[0036] In step S41, based on the grand canonical ensemble theory, the fundamental differential equation of thermodynamics for the particle heat and mass exchange process is obtained, as shown in formula (9):

[0037]

[0038] In the formula, dS is the infinitesimal change in entropy when the system reaches the equilibrium state; U is the internal energy of the system; P is the pressure of the system; V is the volume of the system; μ is the chemical potential of the particle; N is the number of moles of the system; T is the thermodynamic temperature of the system;

[0039] In step S42, according to PV = nRT, the differential form of the entropy change (10) is further obtained:

[0040]

[0041] In step S43, the integral calculation is used to obtain the value from the initial temperature T i to the final temperature T fThe heat change, as shown in Equation (11), is used to construct a calculation model for the infiltration load of heat and mass exchange between the indoor air of the building and the external environment:

[0042]

[0043] In the formula, ΔQ 1 is the heat change value of the indoor air of the building from the initial temperature to the final temperature; m is the mass of air particles, (kg); k is the Boltzmann constant; h is the Planck constant; P is the pressure, (Pa); T is the temperature, (K).

[0044] In the said step S5:

[0045] A calculation model for the heating and cooling loads of the building based on the grand canonical ensemble theory is established, as shown in Equations (12) and (13):

[0046] Q L =CL w +CL c +CL rt +CL zm +CL sb +ΔQ 1 (12)

[0047] Q R =Q 1 +ΔQ 1 (13)

[0048] In the formula, Q L is the cooling load of the building; Q R is the heating load of the building.

[0049] The said step S6 specifically includes the following steps:

[0050] Step S61, use the model established in step S5 to calculate the heating and cooling loads of each building, and at the same time obtain the historical operation data of the heating and cooling loads of the building cluster. Compare the relative error between the two load results according to the time series, and further introduce a correction coefficient η to correct the model;

[0051] Step S62, the corrected calculation models for the heating and cooling loads of each building are shown in Equations (14) and (15). Add up the loads of each individual building in the building cluster to obtain the building cluster load;

[0052] Q L ’=CL w +CL c +CL rt +CL zm +CL sb +ηΔQ 1 (14)

[0053] QR ’ = Q 1 + ηΔQ 1 (15)

[0054] Wherein, Q L ’ is the heat load of the building cluster; Q R ’ is the cooling load of the building cluster.

[0055] The beneficial effects of the present invention are as follows:

[0056] The present invention provides a rapid calculation method for the load of a building cluster. This method not only has the physical clarity of the mechanism model, but also combines the data-driven method, improves the load calculation model in the existing engineering design, carefully models the infiltration load of indoor and outdoor air, can realize the rapid calculation and accurate evaluation of the load characteristics of the building cluster, helps to guide the accurate regulation and operation of the HVAC equipment in the building energy system, thereby effectively reducing the building energy consumption, and has important significance for the energy conservation and emission reduction of the building energy system under carbon peak and carbon neutrality. Description of the Drawings

[0057] The present invention will be further described below with reference to the drawings and embodiments.

[0058] Figure 1 is the flow chart of the method of the present invention.

[0059] Figure 2 is a schematic diagram of a typical application scenario of the load calculation model of the present invention.

[0060] Figure 3 is the comparison of load results and model verification diagram under the heating scenario (a) and air conditioning cooling scenario (b) of the method of the present invention. Detailed Embodiments

[0061] As Figure 1 , the present invention discloses a rapid calculation method for the load of a building cluster, including the following steps:

[0062] Step S1:

[0063] 1) First, obtain the main parameters of the enclosure structures of each individual building in the building cluster, including the composition materials, areas, window-wall ratios, and shape coefficients of the enclosure structures of each part of the building, and determine the heat transfer coefficient K of each part.

[0064] 2) Obtain the weather data of the area where the building is located, including hourly dry bulb temperature, pressure, and wind speed data.

[0065] Obtaining the above data facilitates the subsequent calculation of the building's heating and cooling loads.

[0066] Step S2:

[0067] 1) In the central heating scenario, a one-dimensional steady-state heat transfer equation is constructed for each part of the building envelope, as shown in Equation (1), to obtain the basic heat consumption Q of the building envelope. j .

[0068] Q j = KF(t n - t w )α (1)

[0069] In the formula, K is the heat transfer coefficient of the external wall, roof or external window [W / (m 2 ·K)], F is the heat transfer area of the external wall, roof or external window (m 2 ), t n is the indoor temperature; t w is the outdoor temperature; α is the temperature difference correction coefficient, which can be obtained from the "Code for Heating, Ventilation and Air Conditioning Design of Civil Buildings" (hereinafter referred to as the "Code").

[0070] 2) The actual heat consumption will be affected by different factors such as meteorological conditions and the actual situation of the building, and it is necessary to correct the basic heat consumption. The orientation correction coefficient β ch , the wind load addition coefficient β f and the height addition coefficient β fg of the building are obtained from the "Code", and the actual heat consumption Q 1 is further calculated by Equation (2).

[0071] Q 1 = Q j (1 + β ch + β f )(1 + β fg ) (2)

[0072] Step S3:

[0073] 1) The cooling load formed by the heat transfer of the external wall, roof and external window is calculated through the steady-state heat transfer equation (3):

[0074] CL W = KF(t wl - t n ) (3)

[0075] In the formula, t wl is the hourly cooling load calculation temperature of the external wall, roof or external window.

[0076] 2) Calculate the cooling load formed by the solar heat gain through the external window, as shown in Equation (4):

[0077] CL c = C clC C z D Jmax F c (4)

[0078] C z = C w C n C s (5)

[0079] In the formula, C c is the hourly cooling load formed by the solar radiation heat gain entering through the glass window, C clC is the solar radiation cooling load coefficient of the standard glass without sunshade, C z is the comprehensive shading coefficient of the exterior window, C w is the exterior sunshade correction coefficient, C n is the interior sunshade correction coefficient, C s is the glass correction coefficient, D Jmax is the maximum value of the solar heat gain factor in summer, all of which can be obtained from the "Code", F c is the net area of the window glass (m 2 ).

[0080] 3) The cooling load formed by the heat dissipation of the human body, lighting, and equipment can be calculated according to formulas (6), (7), and (8):

[0081]

[0082] C zm = C clzm C zm Q zm (7)

[0083] C sb = C clsb C sb Q sb (8)

[0084] In the formula, C rt , C zm , C sb are the hourly cooling loads formed by the heat dissipation of the human body, lighting, and equipment, respectively (W); n is the number of people, is the clustering coefficient; are the cooling load coefficients of the human body, lighting, and equipment, respectively, C zm and C sb are the correction coefficients of lighting and equipment, respectively, Q rt , Q zm , Q sb are the heat dissipations of the human body, lighting, and equipment, respectively (W).

[0085] Step S4:

[0086] 1) Based on the grand canonical ensemble theory, the basic thermodynamic differential equation of the particle heat and mass exchange process is obtained, as shown in formula (9):

[0087]

[0088] Wherein, dS is the infinitesimal change in entropy when the system reaches the equilibrium state; U is the internal energy of the system; P is the pressure of the system; V is the volume of the system; μ is the chemical potential of the particles; N is the number of moles of the system; T is the thermodynamic temperature of the system;

[0089] 2) According to PV = nRT, the differential form (10) of the entropy change is further obtained:

[0090]

[0091] 3), the heat change from the initial temperature T i to the final temperature T f is obtained by integral calculation, as shown in Equation (11), and an infiltration load calculation model for heat and mass exchange between the indoor air and the external environment is constructed based on this:

[0092]

[0093] Wherein, ΔQ 1 is the heat change value of the indoor air from the initial temperature to the final temperature; m is the mass of air particles, (kg); k is the Boltzmann constant; h is the Planck constant; P is the pressure, (Pa); T is the temperature, (K).

[0094] Step S5:

[0095] Based on the above steps, a calculation model for building cooling and heating loads based on the grand canonical ensemble theory is established, as shown in Equations (12)(13):

[0096] Q L = CL w + CL c + CL rt + CL zm + CL sb + ΔQ 1 (12)

[0097] Q R = Q 1 + ΔQ 1 (13)

[0098] Wherein, Q L is the building cooling load; Q R is the building heating load.

[0099] Step S6:

[0100] 1) Calculate the heating and cooling loads of the building using the model established in step S5. At the same time, obtain the historical operation data of the heating and cooling loads of the building cluster, compare the relative error between the two load results according to the time series, and further introduce a correction coefficient η to correct the model.

[0101] 2) The corrected building heating and cooling load calculation model is shown in equations (14) and (15). Superimpose the loads of each individual building in the building cluster to finally obtain the load of the building cluster.

[0102] Q L ’ = CL w +CL c +CL rt +CL zm +CL sb +ηΔQ 1 (14)

[0103] Q R ’ = Q 1 +ηΔQ 1 (15)

[0104] In the formula, Q L ’ is the heating load of the building cluster; Q R ’ is the cooling load of the building cluster.

[0105] As can be seen from Figure 3 (a), in the heating scenario, compare the historical data of the building heating load with the heating load calculation result of the model in the present invention to obtain a comparison chart of the two data and the corresponding time series chart of the correction coefficient. Then, in the cooling scenario, use the obtained correction coefficient to correct the cooling load calculation result of the model, and compare it with the historical data of the building cooling load. As can be seen from Figure 3 (b), the two results are highly consistent, verifying the accuracy of the constructed model.

Claims

1. A rapid calculation method for the load of a building cluster, characterized in that, it includes the following steps: Step S1, obtain the main parameters of the enclosure structures of each individual building in the building cluster and weather data, which is convenient for calculating the heating and cooling loads of the buildings; Step S2, construct a one-dimensional steady-state heat transfer equation, calculate the basic heat consumption of the building enclosure structure, and make additional corrections from three aspects: orientation, wind force, and height; Step S3, use the cooling load coefficient method based on the Z transfer function to calculate the cooling load formed by heat transfer through the enclosure structure and solar heat gain through the exterior windows, as well as the cooling load formed by heat dissipation from the human body, lighting, and equipment; Step S4, based on the grand canonical ensemble theory, construct a calculation model for the infiltration load of heat and mass exchange between the indoor air and the external environment of the building, and calculate the infiltration load; Step S5, comprehensively combine the above steps to establish a calculation model for the heating and cooling loads of the building based on the grand canonical ensemble theory; Step S6, obtain the historical data set of the heating and cooling loads of the building, compare the load calculation results of the model constructed in S5, introduce a correction coefficient η to correct the model, and superimpose the loads of each individual building in the building cluster to obtain the load of the building cluster; The specific steps of the said Step S4 include the following steps: Step S41, based on the grand canonical ensemble theory, obtain the basic differential equation of thermodynamics for the heat and mass exchange process of particles, as shown in Equation (1): In the formula, dS is the differential change in entropy when the system reaches the equilibrium state; U is the internal energy of the system; P is the pressure of the system; V is the volume of the system; μ is the chemical potential of the particles; N is the number of moles of the system; T is the thermodynamic temperature of the system; Step S42, according to PV = nRT, further obtain the differential form of the entropy change (2): Step S43, calculate the heat change from the initial temperature T i to the final temperature T f by integral calculation, as shown in Equation (3), and thus construct an infiltration load calculation model for the heat and mass exchange between the indoor air of the building and the external environment: Where, ΔQ 1 is the heat change value of the air inside the building from the initial temperature to the final temperature; m is the mass of air particles, with the unit of (kg); k is the Boltzmann constant; h is the Planck constant; P is the pressure, with the unit of (Pa); T is the temperature, with the unit of (K).

2. A rapid calculation method for the load of a building cluster according to claim 1, characterized in that, in the said Step S1: The main parameters of the enclosure structures of each individual building include the composition materials, areas, window-wall ratios, shape coefficients, and heat transfer coefficients K of each part of the building enclosure structure; The weather data is the weather data of the area where the building is located, including hourly dry bulb temperature, pressure, and wind speed data.

3. A rapid calculation method for the load of a building cluster according to claim 2, characterized in that, the specific steps of the said Step S2 include the following steps: Step S21, in the central heating scenario, construct a one-dimensional steady-state heat transfer equation for each part of the building envelope, as shown in Equation (4), to obtain the basic heat consumption Q of the building envelope j : Q j = KF(t n - t w )α(4) Wherein, K is the heat transfer coefficient of the external wall, roof or external window [W / (m 2 ·K)], F is the heat transfer area of the external wall, roof or external window (m 2 ), t n is the indoor temperature; t w is the outdoor temperature; α is the temperature difference correction coefficient, which can be obtained from the "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings", hereinafter referred to as the "Code". Step S22, correct the basic heat consumption Q j According to the "Code", obtain the orientation correction coefficient β ch of the building, the wind force additional coefficient β f and the height additional coefficient β fg , and further calculate the actual heat consumption Q 1 by Equation (5): Q 1 = Q j (1 + β ch + β f )(1 + β fg ) (5).

4. A rapid calculation method for the load of a building cluster according to claim 3, characterized in that, the specific steps of the said Step S3 include the following steps: Step S31, calculate the cooling load formed by heat transfer through the exterior wall, roof, and exterior windows through the steady-state heat transfer equation (6): CL W = KF(t wl - t n )(6) where t wl is the hourly cooling load calculation temperature of the external wall, roof or external window; Step S32, calculate the cooling load formed by solar heat gain through the exterior windows, as shown in Equation (7): CL c = C clC C z D Jmax F c (7) C z = C w C n C s (8) In the formula, CL c is the hourly cooling load formed by the solar radiation heat gain entering through the glass window; C clC is the solar radiation cooling load coefficient of the standard glass without sunshade, C z is the comprehensive shading coefficient of the outer window, C w is the sunshade correction coefficient, C n is the interior sunshade correction coefficient, C s is the glass correction coefficient, D Jmax is the maximum value of the solar heat gain factor in summer, all of which can be obtained from the "Code", F c is the net area of the window glass (m 2 ); Step S33, the cooling load formed by heat dissipation from the human body, lighting, and equipment can be calculated according to formulas (9), (10), and (11): where, CL rt , CL zm , CL sb are the hourly cooling loads formed by the human body, lighting, and equipment heat dissipation, with the unit of W; n is the number of people, is the clustering coefficient; are the human body, lighting, and equipment cooling load coefficients respectively; C zm and C sb are the lighting and equipment correction coefficients respectively; Q rt , Q zm , Q sb are the heat dissipations of the human body, lighting, and equipment respectively, with the unit of W.

5. A rapid calculation method for the load of a building cluster according to claim 4, characterized in that, in the said Step S5: Establish a calculation model for the heating and cooling loads of the building based on the grand canonical ensemble theory, as shown in Equations (12) and (13): Q L = CL w + CL c + CL rt + CL zm + CL sb + ΔQ 1 (12) Q R = Q 1 + ΔQ 1 (13) In the formula, Q L is the building cooling load; Q R is the building heating load.

6. A rapid calculation method for the load of a building cluster according to claim 5, characterized in that, the specific steps of the said Step S6 include the following steps: Step S61: Calculate the heating and cooling loads of each building using the model established in Step S5. At the same time, obtain the historical operation data of the heating and cooling loads of the building cluster, compare the relative error between the two load results according to the time series, and further introduce a correction coefficient η to correct the model; Step S62: The corrected calculation models for the heating and cooling loads of each building are shown in Equations (14) and (15). By superimposing the loads of each individual building in the building cluster, the load of the building cluster can be obtained; Q L ’ = CL w + CL c + CL rt + CL zm + CL sb + ηΔQ 1 (14) Q R ’ = Q 1 + ηΔQ 1 (15) Where Q L ’ is the heat load of the building cluster; Q R ’ is the cooling load of the building cluster.

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